The invention relates to a bearing for an open-end spinning rotor, the shaft of which is radially held by means of supporting disks and with its end is axially supported at a ball which in turn is supported on the opposite side by means of a pin-shaped abutment arranged as an extension of the shaft. This abutment has a ball-socket-shaped guiding surface for the ball and a clamping point at a distance from it. The abutment is divided into finger-shaped parts by means of at least one longitudinal slot starting from the guiding surface.
In the case of a bearing of the initially mentioned type disclosed in German Patent Document DE-C 25 14 734, it is known to indicate preferred vibrating directions by means of a special shaping and to determine the natural frequencies of the finger-type parts. In this case, it is also known to place the slot such that the finger-type parts have different natural vibrations so that they are excited by different machine vibrations. It is also known to arrange the slot in the center so that the two finger-type parts are excited to perform vibrations when the frequencies are the same.
It is an object of the invention to develop a bearing of the initially mentioned type such that, at rotational speeds of the open-end spinning rotor of more than 100,000 min.sup.-1, a sufficient service life particularly of the axial bearing is obtained.
This object is achieved in that the finger-type parts are designed such that they have natural frequencies which slightly differ from one another and permit a beat.
By means of this construction, it is achieved that the finger-type parts vibrate not only at one excitation frequency, but also at excitations in a larger frequency range. It is sufficient for one of the finger-type parts to be excited to perform a vibration so that, by means of a beat, it will then also excite the other finger-type part.
In a further development of the invention, it is provided that the natural frequency of the one finger-type part differs by less than 10 percent from the natural frequency of the other finger-type part. As a result, a sufficiently larger frequency range is achieved for the exciting vibration.
In a further development of the invention, it is provided that the finger-type parts have a natural frequency of between 4,000 Hz and 5,000 Hz, and preferably of approximately 4,400 Hz. It was found that these natural frequencies are to be preferred for the currently customary dimensions of open-end spinning rotors.
In an advantageous embodiment of the invention, it is provided that the pin-shaped part of the abutment has a diameter of approximately 8 mm, a slot of a length of approximately 20 mm and of a width of approximately 4 mm and is assigned to a ball with a diameter of approximately 12 mm.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.